Minions, the spinoff/prequel of Universal Pictures’ Despicable Me movies, begins, fittingly enough, at the very beginning: In a protean sea, single-celled creatures compete and evolve, predators and prey growing in tandem. But who’s that there, dangling off the tail fin of a particularly wicked-looking fish? Why it’s a minion, one of those little lemon Tic Tacs of servility who worked for the supervillain Gru in the prior films. A narrator (Geoffrey Rush) explains that while not all minions are created alike—some have one eye, some two; some are taller, some rounder—“they all share the same goal: to serve the most despicable master they can find.”

Cue history. The minions graduate from fish groupies to dinosaur groupies, before taking an inevitable step backward with the arrival of human beings. Caveman, pharaoh, vampire, Napoleon—all are tried on for size as masters, but none quite fit. So the minions retreat to an arctic cavern, where they build their own society in seclusion.

But something is still missing. The minions are like rogue planets lost in space, bereft of a star to orbit. So three members of the colony—Kevin, Stuart, and Bob—set out to find a suitably despicable master. (All of the minions are voiced, as before, by director Pierre Coffin, in their distinctive pidgin mishmash of English, Spanish, French, Italian, and sheer gibberish.)

The year is by now 1968, which means that the Minions soundtrack will make amiable (if not terribly imaginative) use of the Rolling Stones, The Who, the Doors, the Beatles, The Spencer Davis Group, and the theme song from Hair. The minions first arrive in New York, but while flipping channels on a department-store TV—The Saint, Bewitched, The Dating Game—they stumble across a secret channel announcing the upcoming Villain-Con convention to be held in Orlando. (In one of the movie’s better gags, 1968 Orlando is portrayed as essentially an empty swamp.) At Villain-Con, the minions meet and sign on with the world’s self-described greatest supervillain, Scarlet Overkill (Sandra Bullock), who whisks them off to London, where the central plot will unfold. Because, you know: groovy, baby.

There, Scarlet and her doting husband, Herb Overkill (Jon Hamm), charge the minions with stealing Saint Edward’s Crown from Queen Elizabeth II (Jennifer Saunders). As an additional incentive, Scarlet makes clear that if they fail, she will be slicing herself some filet minion. Hijinks ensue, as Kevin, Stuart, and Bob bounce from the Tower of London to the site of Excalibur to Westminster Abbey. Double-crosses (some inadvertent) are perpetrated on all sides, and chase scene follows closely upon chase scene.

There’s plenty of high-velocity comic inanity on display to keep kids happily diverted, and the minions themselves are consistently amusing. (Though, unsurprisingly, they demonstrate that they’re better suited to be comic grace notes than full-on protagonists.) The movie’s major problem is an extension of its own premise: Search as they may, the minions never find a villain worthy of their subservience. Scarlet Overkill is a slapdash figure who never coheres as a character, and Bullock isn’t a gifted enough comedienne to elevate the material she’s been given. (Kristen Wiig was far better in a less-central role in Despicable Me 2.) And casting Hamm as Scarlet’s debonair, man-of-the-sixties husband is a one-note gag that never finds its proper key.

This discrepancy between Minions and the Despicable Me movies is made all too clear at the very end, when the film comes full circle and a new villain briefly appears on the scene, a young boy with a beak-like nose and an accent of indeterminate Eastern European origin. The minions recognize his qualities immediately, and so do we: Finally—but alas, too late for this installment—a master whose despicability is beyond reproach.